I can understand why SE made the cutscenes in the MSQ roulette unskippable. Back when I did those dungeons for the story it was a huge culture shock after the earlier 4-player dungeons where people generally took care that no one was left behind because of cutscenes or dying. The experience was so appalling that I considered quitting the game then and there. On the other hand I also understand that watching the long cutscenes can feel like a waste of time when there are no new players along on the run. Making them unskippable seems like they went from one extreme to another.
Another issue I have with cutscenes is that when I have autoskip enabled and enter a dungeon or raid I've done previously but someone else is new, I have to wait at the beginning doing nothing while they watch the cutscene. I would rather watch the cutscene myself. But I don't want to be the one holding everyone else up with a cutscene I've seen before so out of courtesy I keep autoskip enabled.
My proposal is to add a "vote to skip" option when you press esc during the cutscene (or the B button, or whatever symbol is used on PS4). If you select that option you'll continue watching the cutscene but a flag is set that you want to skip it. If everyone agrees to skip, the cutscene ends immediately. The "yes" option will end the cutscene immediately for you only as it does now (and also set the flag); it could be changed to "skip immediately" to make the meaning more clear. The autoskip option should also get an additional checkbox to automatically vote to skip.
With this change I would have something to keep me entertained while the new player watches their cutscene. If no one is new the cutscene would be skipped as before. And those that would rather skip immediately and sort their inventory or something could keep doing that as before. Everyone would win.